New protection against tuberculosis

Tuberculosis (or TB) is a huge global problem, especially in developing countries, where access to antibiotics to treat the disease is limited.

TB is usually a disease of the lungs (although it can attack any part of the body). Pulmonary TB causes a bad cough, chest pains and weight loss. Some patients cough up blood or sputum. Untreated, it can be deadly. However, only in a small number of cases - fewer than 5% - do the symptoms develop immediately after infection. In more than 90% of cases, when Mycobacterium tuberculosis, the bacterium which causes the disease, has invaded the body it changes its chemical signature, and lives in a latent state.

Usually the bacterium never emerges from this latent state, but in around 10% of cases it reactivates - often years or even decades later - to trigger severe symptoms.

Current vaccines, such as the BCG vaccine, do not prevent infection, but do prevent acute symptoms and disease from emerging.

Developed at the Statens Serum Institute in Copenhagen, the new vaccine combines proteins that trigger an immune response to both the active and latent forms of Mycobacterium.

Professor Peter Davies said: " A vaccine which can both protect against initial infection and protect from its turning into disease is a major breakthrough.

" One of the main disadvantages of BCG was that it could only prevent infection going on to disease in the initially uninfected individual. It was therefore of no use in protecting infected adults who would become an infectious source of disease. Protecting children, though it is important, does not protect against transmission, as children with active disease do not usually transmit disease.

" With over 9 million new TB cases globally each year and increasing levels of drug resistance, new diagnostics, drugs and especially effective vaccines are really needed."

1. Extract the necessary information from the article and fill in the table. If any information is not available, put “—“.

Answer the questions about the research project described in the article.

1. Looking for new ways of preventing TB is of vital importance. Why?

2. Are there any TB vaccines available?

3. Do they prevent infection? Why / why not? Explain the mechanism.

4. How about the new vaccine developed in Sweden? What does it protect from?